Methods for evaluating and covering the design space during early design development

This paper gives an overview of methods used for Design Space Exploration (DSE) at the systemand micro-architecture levels. The DSE problem is considered to be two orthogonal issues: (I) How could a single design point be evaluated, (II) how could the design space be covered during the exploration process? The latter question arises since an exhaustive exploration of the design space by evaluating every possible design point is usually prohibitive due to the sheer size of the design space. We therefore reveal trade-offs linked to the choice of appropriate evaluation and coverage methods. The designer has to balance the following issues: the accuracy of the evaluation, the time it takes to evaluate one design point (including the implementation of the evaluation model), the precision/granularity of the design space coverage, and last but not least the possibilities for automating the exploration process. We also list common representations of the design space and compare current system and micro-architecture level design frameworks. This review thus eases the choice of a decent exploration policy by providing a comprehensive survey and classification of recent related work. It is focused on System-on-a-Chip designs, particularly those used for network processors. These systems are heterogeneous in nature using multiple computation, communication, memory, and peripheral resources.